JS: add checker that checks if JsQualifier has wrong format

compiler/testData/diagnostics/testsWithJsStdLib/qualifier/wrongQualifier.kt

@@ -0,0 +1,17 @@
+// FILE: a.kt
+@file:JsQualifier(<!WRONG_JS_QUALIFIER!>""<!>)
+
+// FILE: b.kt
+@file:JsQualifier(<!WRONG_JS_QUALIFIER!>"a..b"<!>)
+
+// FILE: c.kt
+@file:JsQualifier(<!WRONG_JS_QUALIFIER!>"a."<!>)
+
+// FILE: d.kt
+@file:JsQualifier(<!WRONG_JS_QUALIFIER!>".a"<!>)
+
+// FILE: e.kt
+@file:JsQualifier(<!WRONG_JS_QUALIFIER!>"%^&"<!>)
+
+// FILE: f.kt
+@file:JsQualifier("a.bc.d23._$")

compiler/testData/diagnostics/testsWithJsStdLib/qualifier/wrongQualifier.txt

@@ -0,0 +1 @@
+package

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithJsStdLibGenerated.java

@@ -996,6 +996,27 @@ public class DiagnosticsTestWithJsStdLibGenerated extends AbstractDiagnosticsTes
         }
     }
 
+    @TestMetadata("compiler/testData/diagnostics/testsWithJsStdLib/qualifier")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class Qualifier extends AbstractDiagnosticsTestWithJsStdLib {
+        public void testAllFilesPresentInQualifier() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/testsWithJsStdLib/qualifier"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("jsQualifierNonExternal.kt")
+        public void testJsQualifierNonExternal() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/qualifier/jsQualifierNonExternal.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("wrongQualifier.kt")
+        public void testWrongQualifier() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithJsStdLib/qualifier/wrongQualifier.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("compiler/testData/diagnostics/testsWithJsStdLib/reflection")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/JsPlatformConfigurator.kt

@@ -68,5 +68,6 @@ object JsPlatformConfigurator : PlatformConfigurator(
         container.useImpl<JsNativeRttiChecker>()
         container.useImpl<JsReifiedNativeChecker>()
         container.useInstance(ExtensionFunctionToExternalIsInlinable)
+        container.useInstance(JsQualifierChecker)
     }
 }

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsQualifierChecker.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.js.resolve.diagnostics
+
+import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
+import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
+import org.jetbrains.kotlin.psi.KtAnnotationEntry
+import org.jetbrains.kotlin.resolve.AdditionalAnnotationChecker
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.BindingTrace
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+
+object JsQualifierChecker : AdditionalAnnotationChecker {
+    override fun checkEntries(entries: List<KtAnnotationEntry>, actualTargets: List<KotlinTarget>, trace: BindingTrace) {
+        val bindingContext = trace.bindingContext
+        for (entry in entries) {
+            val annotation = bindingContext[BindingContext.ANNOTATION, entry] ?: continue
+            if (annotation.type.constructor.declarationDescriptor?.fqNameSafe != AnnotationsUtils.JS_QUALIFIER_ANNOTATION) continue
+            val argument = annotation.allValueArguments.values.singleOrNull()?.value as? String ?: continue
+            if (!validateQualifier(argument)) {
+                val argumentPsi = entry.valueArgumentList!!.arguments[0]
+                trace.report(ErrorsJs.WRONG_JS_QUALIFIER.on(argumentPsi))
+            }
+        }
+    }
+
+    private fun validateQualifier(qualifier: String): Boolean {
+        val parts = qualifier.split('.')
+        if (parts.isEmpty()) return false
+
+        return parts.all { part ->
+            part.isNotEmpty() && part[0].isJavaIdentifierStart() && part.drop(1).all(Char::isJavaIdentifierPart)
+        }
+    }
+}